SQL Server Error: Could not obtain information about Windows NT group/user

I got this error while trying to create a new database diagram after restoring it from backup. The error indicates that current login does not have authorization necessary to get information about the database owner. This can be easily solved by executing following script

USE MyDB 
GO 
ALTER DATABASE MyDB set TRUSTWORTHY ON; 
GO 
EXEC dbo.sp_changedbowner @loginame = N'sa', @map = false 
GO 
sp_configure 'show advanced options', 1; 
GO 
RECONFIGURE; 
GO 
sp_configure 'clr enabled', 1; 
GO 
RECONFIGURE; 
GO

Copied from: https://stackoverflow.com/questions/25845836/could-not-obtain-information-about-windows-nt-group-user